Second-trimester levels of fetoplacental hormones among women with placenta accreta spectrum disorders

First- and Second-Trimester Aneuploidy Screening Biomarkers and Risk Assessment of Placenta Previa and Accreta: A Systematic Review and Meta-Analysis

OBJECTIVE

This study evaluates differences in first and second-trimester maternal serum biomarkers for aneuploidy screening among women with placenta accreta spectrum (PAS) disorders, placenta previa, and those with normal placentation.

DATA SOURCES

A systematic review of 5 major databases up to April 2023 was conducted. Included were comparative studies analyzing mean biomarker levels in multiples of the median (MoM) among pregnant women with PAS, placenta previa, and uncomplicated pregnancies.

STUDY SELECTION

Both observational studies and randomized controlled trials were included in this meta-analysis.

DATA EXTRACTION AND DATA SYNTHESIS

Analysis of 8 retrospective studies involving 1886 participants showed significant variances in biomarker levels. In the first trimester, pregnancy-associated plasma protein-A levels were notably higher in the PAS group compared to the placenta previa group (731 patients, mean difference (MD) 0.48 MoM; 95% CI 0.23 to 0.73, P = 0.0001). Also, β-human chorionic gonadotropin levels were elevated in the placenta previa group compared to those with normal attachment (362 patients, MD 0.27 MoM; 95% CI 0.17 to 0.38, P < 0.00001). In the second trimester, alpha fetoprotein and human chorionic gonadotropin levels were significantly increased in PAS patients compared to the placenta previa and normal groups, indicating potential markers for PAS.

CONCLUSIONS

Significant differences in early pregnancy biomarker levels among women with PAS, placenta previa, and normal placentation were identified. These findings suggest potential for early screening, but further large-scale studies are essential for validation. This study underscores the need for improved screening methods for placental disorders, potentially aiding in early diagnosis and management strategies.

Diagnostic Role of Cell-Free miRNAs in Identifying Placenta Accreta Spectrum during First-Trimester Screening

Placenta accreta spectrum (PAS) is a severe complication of pregnancy associated with excessive invasion of cytotrophoblast cells at the sites of the endometrial-myometrial interface and the myometrium itself in cases of adherent (creta) and invasive (increta and percreta) forms, respectively. This leads to a high risk of massive blood loss, maternal hysterectomy, and preterm birth. Despite advancements in ultrasound protocols and found associations of alpha-fetoprotein, PAPP-A, hCG, PLGF, sFlt-1, IL-8, and IL-33 peripheral blood levels with PAS, there is a high need for an additional non-invasive test to improve the diagnostic accuracy and to select the real PAS from the suspected ones in the first-trimester screening. miRNA signatures of placental tissue, myometrium, and blood plasma from women with PAS in the third trimester of pregnancy, as well as miRNA profiles in exosomes from the blood serum of women in the first trimester with physiologically progressing pregnancy, complicated by PAS or pre-eclampsia, were obtained using deep sequencing. Two logistic regression models were constructed, both featuring statistically significant parameters related to the levels of miR-26a-5p, miR-17-5p, and miR-101-3p, quantified by real-time PCR in native blood serum. These models demonstrated 100% sensitivity in detecting PAS during the first pregnancy screening. These miRNAs were identified as specific markers for PAS, showing significant differences in their blood serum levels during the first trimester in the PAS group compared to those in physiological pregnancies, early- or late-onset pre-eclampsia groups. Furthermore, these miRNAs exhibited differential expression in the PAS placenta and/or myometrium in the third trimester and, according to data from the literature, control angiogenesis. Significant correlations were found between extracellular hsa-miR-101-3p and nuchal translucency thickness, hsa-miR-17-5p and uterine artery pulsatility index, and hsa-miR-26a-5p and hsa-miR-17-5p with PLGF. The developed test system for early non-invasive PAS diagnosis based on the blood serum level of extracellular miR-26a-5p, miR-17-5p, and miR-101-3p can serve as an auxiliary method for first-trimester screening of pregnant women, subject to validation with independent test samples.

Termination of a second-trimester pregnancy with placenta accreta spectrum disorder

Background: The termination of pregnancy in patients with placenta accreta spectrum disorder (PASD) during the second trimester remains uncertain. In addition, interventional radiology techniques, such as arterial embolization and balloon placement, are potential options. We evaluated the outcomes of pregnancy termination in patients with PASD during the second trimester and the effectiveness of preoperative interventional radiology techniques.Methods: This retrospective study analyzed 48 PASD patients who underwent pregnancy termination during the second trimester between January 2016 and May 2021.Results: Of the 48 patients, 20 (41.67%) underwent transvaginal termination, whereas 28 (58.33%) underwent cesarean section. Notably, no significant differences were observed in success rates between the transvaginal termination and cesarean section groups (80.00% vs. 92.86%, P = 0.38). Furthermore, no statistically significant differences were observed in the success rates (94.12% vs 90.32%, P = 1.00) and blood loss (512.35 ± 727.00 ml vs 804.00 ± 838.98 ml, P = 0.23) between the artery embolization and non-embolization groups. In the vaginal termination group, statistically significant differences were observed in gestational weeks (16.70 ± 3.12 vs 22.67 ± 3.63, P < 0.01) and blood loss (165.00 ± 274.43 ml vs 483.64 ± 333.53 ml, P = 0.04) between the (artery embolization and non-embolization) subgroups. Conversely, in the cesarean section group, no significant differences were observed in gestational weeks (23.59 ± 3.14 vs 23.20 ± 4.37, P = 0.79) and blood loss (811.11 ± 879.55 ml vs 989.47 ± 986.52 ml, P = 0.76) between the subgroups.Conclusions: Further studies are needed to evaluate the efficacy of vaginal termination in PASD patients during the second trimester. Regarding cesarean termination, arterial embolization did not demonstrate increased effectiveness.